The present technique relates to a transfer device, an information processing apparatus including an I/O board connected to a system board and a peripheral device and equipped with the transfer device, a method of controlling the transfer device, and a method of controlling the information processing device.
Some information processing devices have such a configuration that physically separated units are incorporated. Examples of the units include a system board equipped with a CPU (central processing unit) or a memory, and an I/O board equipped with an I/O (input/output) device for a hard disk drive or PCI (peripheral component interconnect) device. Cross bar switches including an address crossbar switch and a data crossbar switch are mounted onto the system board and the I/O board to increase a data transfer rate. The address crossbar switch functions to merge and arbitrate address requests sent from the system board or the I/O board, and functions to broadcast the merged address requests to all of the system board and the I/O board.
In such information processing apparatuses, one cashing can be divided into plural partitions where systems independently operate. Thus, the partitions have different operating systems (OS's), and plural systems can be configured in one casing.
The information processing apparatus may have mirror configuration obtained by dividing the entire system into mirror areas having the same partition configuration. However, if a system having mirror configuration and a system not having mirror configuration coexist, data cannot be synchronized because of a shared portion like the address crossbar switch. Thus, even though any system is adaptable to a partition scheme, the whole system configuration is limited to the mirror configuration or non-mirror configuration. In other words, a system composed of mirrored partitions and a system composed of partitions being not mirrored cannot coexist in the same casing.
There are Japanese Laid-open Patent Publication No. 09-006737, Japanese Laid-open Patent Publication No. 2001-318901, and Japanese Laid-open Patent Publication No. 2004-072547.